Automatic lock for hoisting mechanisms



y 1951 H. A. GEERDS 2,550,801

AUTOMATIC LOCK FOR HOISTING MECHANISMS Filed April 4, 1949 r 4 Sheets-Sheet l I \NVENTOR HENRY A. G'EERDS W Zw ATTORNEYS May 1, 1951 A, EE 2,550,801

AUTOMATIC LOCK FOR HOISTING MECHANISMS Filed April 4, 949 4 Sheets-Sheet 2 30 Q 24 19 l 7 D 5 mum m\ 1\\\ 3 l7 Illll I I? n a In; l5 5 W 1a 5 1 R Q 1 \NVENTOR.

HENRY A. Geeks: Q! k dwv ATTORNEYS y 1951 H. A. GEERDS 2,550,801

' AUTOMATIC LOCK FOR HOISTING MECHANISMS Filed April 4, 1949 4 Sheets-Sheet 3 \NVENTOR HENRY Afieaaos ATTORNEYS y 1951 H. A. GEERDS 2,550,801

AUTOMATIC LOGK FOR HOISTING MECHANISMS Filed April 4, 1949 V 4 S heets-Sheet 4 91L ATTORNEYS Patented May 1, 1951 AUTOMATIC LooK FGRJHO'IS'TING MECHANISMS mration Of Michigan Application April 4,

, 12 claims, e 1 e r This'inv'entionis directed to an aiutoi'ifa; '0 lookihg'or holding means for hoist'ing mecha isms.

The hoisting i'j'acks are used, "in one iial'ace of use thereof, in connection "with trelilers'vvhi'chare d'etach'ably connected Withtr'uks. "Such hoisting jagcks ordinarily moenteuatt eunder'sme of and adjacent the 'front end or seJi'd trailers, b'eing retreated when the trailer is connec'ted'to the truck which pulls it, and eiitehfled when a, He'sfifitioh is reached and the truek is d'isconneet'dTfrom'the tr'tiile'r, the hoisting jeieli supporting the trailer at a proper level and withthe bottomof the body of 'the trailer generally horizontal, the trailer having no other means of su port at its front end.

A'hoisting jack of the typenoted has been bro- ViHed with a, shaft htifili "a Cdiitihueus 'Wdiffi thread at its outer side passi g through 'an interiorly threadedsl'eeve to receive it, the w'oiin being mounted upon one section of the eiztens'ible hoist and the sleeve h anbthrseetibn the" of, the two sections or the hoist being'tuscepea Within the other; Turnirig the ivofm 'shajft may either eiitend or retract the hoist dependifig'uboh the direction bf turning. When the sheit he'sefn outwardly projeeting hlictjl thread f fittiflg eats the interior thr'e'adsb'f the "sleeve; the sleeve and shaft w ll remain in any positionto which eajus ted, in effect b i'bvi difig a 100k 52 in st dci dental or Othi undesired ehaifig fifbbsitifih 01 the "relatiVly eXten Sib I parts bf heist; At the same time the shaft may be 1: ea 'fai such extension or retraction when Wanted. But the force which has to he exerted hi3? he heavy, pei rtililaily in li ft ihg a loaded tieili at its fi'bht end above its connection to a treotor which puns it.

For the purpose of decreasing the force wmah may be used for Operating the hoist there has co'me'into use helicaliy grooved shafts and sleeves in both of which continuous helical grooves are out and with bans seatedin cooperating grooves in the interiorly grooved sleeve and 'theexterioflv grooved shaft Whih greatly reduces friction in turning the shaft. Such construction however does not retain the locking qualities ofthe bro; vious worm thread connection of the sheft sleeve SO that ithas becbihe hees stfy td pi dv id an accessory Took 'vvhi'ch willinsure that the hoist parts do not ohange position relative to ali other either when the trailer is being pui'led over r the Id'ad OI when it is S'tehdiii'g hit a dfibt With the hoist vsupporting the trailer and 115510346 lit its front end. i k V It is an object and purpose of the bresnt in- 1949,Serial No. 85,444

with i... it, i Q. .LZHiH w. H we vention to provide a very efiective end p h ock cithe y e ment pnfidowhiehvis. lee eb on. m nual tu i e he eliqali itogi she f e her qi n t e emrmiw i n Q .9 era qnp h tpa rt butwh hr. 11's? e1? et n th hoi iiW iXPQPiiii IiS DWP Q KPeXF? e lura y 6 time beeperwi i i ermine ob ec and-91 mm; f.;i 3 Zi JYee 9R qep iev e' 100k W ich-is. 0 cenpmie e iru A-.., .r!. eedy 5 durable in service and which is readily and i t e -e i e .o Anm mwiqim vili -.ieyeet s e; ie te ed. rom e e l wine essen e taken n 0 he: i h. tliqaqwiee e iee erwi me e 3 Fig. 1 is an elevation, partly in l ongit diner q l c fii nlpf. 9.119. of t e. 91 teem- 9ers Wh y h use wit a irei m m k vqe ree and in new; w e nv n e e1 li r .1 Yew-W. .j. F -.2 s oni' ni leci qei ipueh w 3 t? 10ck ub e i 'e v t xqplae ,d 112 2312. Fit? 3 th e em Qf iiltee fi qei ing Qw ei ney rnidwey betweenthe inner and outer sides of the mek hbus n'g,

,Fig. 3 is "a verti 31 section su fie iii fi the cr th nner as e si ne nt si w i d 1 9 9 1%" of the hand 'crenk wmeh ieo ii ii i iena, eit l 1. NEW WWI? 69 t emedifi q' and preferred form of construe on; including o 9 fieiife fii iet .t fi ih i i housing and the associated-Make, at one side of h v w if e A '10 is a bersbect ive view of the braking eleti v A. .t an iit Lik h e e at fe f were. lik art iii th l f iifi e 9UP? raw n s m ee t ns b'le d eriaaeie e n hqi ttmeqhar 12 t ee ev ch e fieq mally used in. t j. la e t a l r dra s b trucks in re ght t esnert r 5: i a ben s tween a ed he ls I;

mounted in connection with a suitable axle housing 2, between which wheels a vertical and generally hollow tubular member 4 permanently connected at its upper end to a gear housing casting associated one with each of the chassis frame members of the trailer body. An exterior helically grooved shaft 6 at its upper end portion passes through the bottom of the gear housing 5 and is rotatably mounted therein and at its lower grooved portion passes through an interiorly grooved sleeve 1 permanently secured at the upper end portion of the post 3. Balls 8 fill the complementary grooves of the shaft 6 and sleeve 1 for the length of said sleeve. When the shaft 6 is rotated the sleeve 1 moves along said shaft 6 in the direction of its length moving upwardly in one direction of the turning of said shaft and downwardly in the other. The details of the movement of the balls 8 and how they are controlled need not be entered into as such structure is :old and well known.

At the upper end of the shaft 6 a beveled pinion 9 is keyed or otherwise fixedly secured, which meshes with a second beveled pinion |ll keyed to a horizontal shaft H which passes through a suitable bearing for it in a side of the gear housing 5 and adjacent chassis side frame member. A universal joint l2 connects said shaft H, which is of short length, at its inner end with an equalizing shaft |3 which extends to a like hoisting unit associated with the other side chassis frame member of the trailer body, whereby a rotation ofjshaft raises or lowers the telescoping posts 3 and wheels I associated therewith simultaneouslyand in equal amounts. With the previously mentioned worm shaft and sleeve used in which no additional lock is required, said shaft would continue through the housing and be rotatably mounted adjacent its outer end in a second bearing in the opposite side of the housing 5, and at its outer free end portion be equipped with a crank to turn the shaft. With my invention the shaft extends nearlyto but terminates short of th e opposite vertical side or the housing 5. The lockingmechanism of my invention is mounted at the outer vertical 5 .o l l p s e Q f Sa lo'cking mechanism includes a generally box structure having a verticalplate M at its inner side,. fr om which a square surrounding enclosure having sides |5 extending outwardly are cast integrally with the plate l4. The outer open side o'f'this box is covered by, a second vertical plate 6, theplates, I4 and I6 having outwardly extending ears, as indicated by the ears Mo on the plate M (Fig. 3) between which ears sleeve collars H are located. Headed screws l8 pass through openings in the plate l6 and said-ears into'interiorly threaded openings bored to receive their inner ends in the gear housing 5 (Fig. 1).. Each of the sides |5 of the box, substantially at its middle is provided with an inner generally semi-circular groove or recess l9, each having the same radius of curvature as the inner corners at the meeting ends of thesides |5 of the box and are of rounded form as shown.

A circular plate 2|] islocated in the box against the inner plate M and may freely turn about a horizontal axis. The plate has a central opening through it and a hollow sleeve hub 2| extends therefrom through the plate I4 and through a bearing in the adjacent side of the'gear housing 5.- The adjacent end of the shaft II is reduced in diameter to enter the sleeve 2| (Fig. 2), a bolt passing through the sleeve and the end of the 4 shaft II to securely connect said sleeve and shaft together. From the plate two spaced pins 22 extend outwardly, both being located to one side of a diameter of the plate (Fig. 3).

Against the circular plate 22 a floating locking member 23 is positioned, of irregular shape as best'shown in Fig. 3, and which at one end is equipped'with a roller 24 mounted on an outwardly extending pin, the roller having a radius of curvature corresponding to the radius of curvature of the recesses l9 and of the inner corners of the box described. At the opposite end of the floating member 23, which is made from a flat plate of metal, an idle grooved roller 25 is mounted on a supporting pin which extends outwardly from the member 23. A coiled tension spring 26 has its ends connected with the pins 22 and rides between its ends in the groove of the roller 25. Said floating member 23, at opposite sides between the rollers 24 and 25, has oppositely projecting fingers 21 which at their inneredges in conjunction with the edges of the plate 23 provide recesses into which the pins 22 may be received. The floating member 23 also has two spaced pins 28 extending outwardly therefrom, of a smaller diameter than the pins 22, one at each side of a somewhat elongated slot 29 formed through the locking member 23, having its longitudinal axis substantially coincident with a line joining the axes of the pins on which the rollers 24 and 25 are mounted.

The outer closure plate I6 of the box which houses the locking mechanism has a central hub through which a short shaft 30 rotatably passes. Such shaft, at its inner end portion, passes through the slot 29 and has a reduced inner end which is rotatably received in the sleeve 2| of the plate 20. A relatively heavy and short rod 32 is connected with the shaft 30, extending radially therefrom, and lies at the outer side of the locking member 23. It is of a length that when the shaft 30 is manually operated by the crank 3| secured at its outer end, the rod 32 comes against pins 22 and 28, those at the right of the shaft 30 (Fig. 3) in one direction of turning movement,-and those at the other side of said shaft 3|] in the opposite direction of movement. The roller 24 may be in any corner of the box hous ing, bein shown in one corner thereof in Fig. 3, or it may be in any one f the recesses l9 at the conclusion of a crank rotation of the shaft 30 in either direction.

With the movable locking plate in a position such that the roller 24 thereon is seated in one of the eight seats therefor at the inner side of the lock housing, spring 26 acting on the plate moves it so that roller 24 will enter such seat as it comes to it. On turning the crank 3| so as to rotate the short shaft 30in a clockwise direction (Figs. 3 and 4), the radially extending rod 32 first strikes a pin 22 on the plate 20 and continues in contact therewith until and after it engages the adjacent pin 28 on the floating locking plate 23 after which two members 20 and 23 turn in unison. The roller 24 (Fig. 4) follows the inner side of the adjacent sides i5 of the lock housing with a movement of the locking plate 23 such that the slot 29 is progressively changed in position with relation to the shaft 30 until a recess l9 is reached whereupon the roller 24 enters such recess; and if the extension of the hoist is as much as wanted, will remain in such recess on cessation of the operation of the crank 3|. However, the operation of the crank 3| may be continued and the'two members 20 and 23 turned acne-poi:

as-.-=f1ar as wanted and "through any number of fluence of either the weight of posts 3 or the load.

supported thereon, bythe .interposition of roller 24 in a recess 59 at an are greater than the arc of travel of pin 22.:Hence on shifting ofload direction, the rotation of shaft 6 is limitedto the distance provided for the transfer of contactbetween the opposite "finger 27 and pin 22; The tension of spring- 26 maintains the roller 25 in its recess during the transfer period.

To reverse the operation, the crank 35 is turned in the opposite directionwhich causes the shaft 30 to move counter-clockwise (Figsj and '6) the opposite pin 28 being firstengaged by the radially extending rod 32 followed shortly after by engaging "the other pin '22. While the locking plate 23 may have a limited rocking movementwith respect to the plate 23 against which it is located, it is only that which is permitted by the position of the fingers 2i and the pin receiving recess between such fingers and the plate 23 of which they are an integral part. Thus if a rotation of the crank 3| should be stopped with the roller in the position shown in Fig. 4 the force of spring 26 would cause the locking plate 23 to be turned counter-clockwise so as to seat in the adjacent corner recess, while if the roller 24 was at the opposite side of the intermediate recess 1-9 the plate 23 would be rocked by the spring 26 to move the roller to the adjacent corner seat for it. Of course if the roller 24 is in a recess l9, as in Fig. 6, the locking dog will remain fixed and any change of position of the shaft 6 will be only until a pin 22 is in a recess at one of the nngers 21.

In Figs. 7 to 10 inclusive, the surrounding enclosure f5 of the previously'described structure, is made of circular form as at I5a, and the semicircular recesses is at the inner side thereof are greatly increased in number as at l9a (Fig. 7)

and are in close succession one after the other;

The'circular plate Zila in place of the previously described plate 2c, atone side hasa radially disposed slot 33'from the edge thereof inwardly for a" distance, and at the slot at one side the plate has anoutward projection as shown in Fig. 7.

A braking elementof a strong wire or wire rod, oran equivalent, has an end portion formed as a generally-radially disposed finger 3 3 which enters the slot 33. The braking element is'of an approximately circular form, as indicated at 35,

and normally springs outward to seat in a V- shaped groove therefor at the inner side of the enclosure, lEa between the inner ends of the recesses Ida and the bottom M of the enclosure.

Such braking element extends around the inner roller and connected with the pins Z2 on plate,

IKDI

Zfla eare substantially the same, :r'oller .24l'being adapted to successively-seat :in the recesses |9a.:

The pin 32 on the-shaft 30,.previously described, is replaced by adifferently shapedprojection 32a, serving the same purpose.

From the shaft an arm 31 extends radially outward reaching nearly to the'inner side of the enclosure 15a, and having a free end which, the movement of the arm in one direction, comes against the finger 36 of the brake element, By pressing thereagainst, the generally circular braking element .35 is contracted and in a great measure pulled away from the groovein theinner.

side of the wall of the enclosure [5a. Therefore, on a rotation of the shaft 30 in a counter-clockwise direction, with reference to Fig. 7, the

greater'succession of seatings of the roller .24 in.

the greater number of recesses 19a which .receive'it. I In the opposite direction, or the clockwise movement of the shaft 30 with reference toFig. '7, the arm 31 moves away from the finger 36, releasing the brake so that it transmitts its fullretarding or braking effect against the wall of the enclosure a and thereby checks abrupt jars or shocks as the roller 24 moves from-one recess l'9a tofithe next succeeding recess. Such jars otherwise take place and, under certain load conditions of a trailer, may take place to a'degree with the first described structure that is undesirable. Therefore, the structure illustrated in Figs. 7 to 10 inclusive is a preferred structure, having the same ease of operation :in one direction of turning -of the shaft 3 0 by the crank 31 connected to it Fig. 1), while in the other direction the weight of thelo-ad will serve to overcome what might be a heavy expenditure of effort required by the operator to manually turn the shaft 30 if there were noload. But the operator is not required to expend excess energy in attempting to soften jars or shocks occurring as the load is lowered, because the braking serves to soften and check and substantially eliminate such jars 0r shocks coming therefrom as the roller 24 moves from one-recess [Sate another next adjacent.

With the construction described the ease of operation of the hoist provided by the ball and groove mechanism of the shaft 6, sleeve .7 and balls -8 is retained and the hoist in the position.

to which it is extended or retracted maintaining such pos tion. The structureis novel, economical to produce, easily installed and has a long life of service. It has provenvery practical and effective forthe purposes for which it has been produced.

The invention is defined in the appended claims and is to be considered comprehensive of all forms of structure coming within their scope.

-I claim:

1. In a structure as described, a box-like housing having a bottom and outer closure with sides at an angle to each other, each of said sides having a recess therein and each of the corners at the juncture of sides of the box having a similar recess, a plate located within the housing adapted to be connected to a shaft which is to.

be releasably held in a position to which turned, two spaced pins secured to and extending from said plate, a floating plate member located against a side of the first plate having means at one end adapted to seat in any of said re-'- cesses, said floating member, between its ends,

having a longitudinal slot closed at both-ends, two

asa eor spaced pins extending from said floating member, a resilient elastic member extending between the pins on said first plate, means projecting from said floating member adjacent its opposite end, said yielding resilient means bearing against the outer sides thereof, to normally move the floating member in a direction to move its recess engaging means toward the sides of said housing, a short shaft extending into said housing through the outer closure thereof, and a rod connected to said shaft and extending radially therefrom adjacent said floating member, having a length so as to engage against all of said pins, and means for manually turning the shaft.

2. A structure as defined in claim 1, saidfirst plate having a hollow hub at its middle portion extendin through and rotatably mounted on the bottom of the housing, said hub being permanently secured to the first mentioned shaft, and said short shaft having a reduced inner end portion rotatably mounted in the inner end of said hub.

3. A structure as defined in claim 1, said first plate being of circular form and the pins carried thereby being spaced from each other an are distance of less than 180, and said pins on the floating member being spaced from each other an arc distance of substantially 180.

l. A structure as defined in claim 1, and two fingers located one at each side of said floating member, forming with the adjacent edges of said floating member, open hooks providing recesses inwhich said first mentioned pins on said first plate are adapted to be received.

5. A device of the class described comprising, a box-like housing of substantially square form having an inner bottom, side walls at right angles to said bottom and an outer closure over the outer side of the housing, said walls each having an arcuate recess therein at its inner side, and each of the inner corners of the housing being of an arc-shape having substantially the same radius or curvature as the recesses, a circular plate located against the inner side of the bottom of the housing having a hollow sleeve hub extending through said bottom, a shaft extending through the closure of said housing and rotatably mounted therein having an inner reduced end rotatably entering said hub, a floating member comprising a flat member of metal located against the outer side of said plate, said floating member having a slot with closed ends through which the shaft passes, a roller at one end of the floating member adapted to enter any of said recesses in the sides of the housing to which brought or seat in the corners thereof, yielding spring means between said plate and floating member pressing said roller outwardly to engage the inner sides of the housing, and means projecting from said plate and said floating member combined with means carried by said shaft to engage therewith on rotation of the shaft for turning said plate and for turning and longitudinally moving said floating member.

6. A structure as defined in claim 5, said means on the plate and on said floating member comprising two spaced apart pins secured to the plate and extending outwardly therefrom and two additional pins spaced from each other fixed to said floating member and extending outwardly therefrom between its ends and disposed nearer the axis of said shaft than the pins on said plate, and said means on the shaft comprising a radial arm secured to said shaft and lying over the outer side of said floating member, said pins being located in the path of movement of said arm on rotation of the shaft.

7. A structure as defined in claim 6, and two fingers, one at each side of said floating member, located between opposite ends thereof, said fingers forming with the floating member open hooks into which the pins on said plate are adapted to be received.

8. In a structure as described, a box-like housing having a bottom and outer closure and side wall between, said side wall having recesses at the inner sides thereof, a plate located within the housing adapted to be connected to a shaft which is to be releasably held in a position to which turned, a floating plate membe located against a side of the first plate having means at one end adapted to seat in any of said recesses, said floating member between its ends having a longitudinal slot, yielding means moving said floating member in a direction to seat said means at its end in a recess when opposite it, a short shaft extending into said housing and through said slot in the floating member, and cooperating means on the shaft and said first plate for turning said first plate by said shaft, substantially as described.

9. A structure as defined in claim 8, and a resilient brake member connected at one end with said first plate and normally pressing against the inner sides of said housing wall, being movable with said first plate on movement thereof to frictionally resist such movement in one direction, and a member connected to said short shaft and movable therewith engageable with said brake member on rotation of the short shaft in the opposite direction, to contract the brake member and permit free rotative movement of said first plate.

10. In a structure as described, a box-like housing having a bottom and outer closure with side walls between them, said walls having a plurality of recesses therein at the inner side, a generally circular plate located within the housing adapted to be connected to a shaft which is to be releasably held in a position to which turned, two spaced pins secured to and extending from the plate, a floating plate member located against a side of the first plate, having means at one end adapted to seat in any of said recesses, said floating member between its ends having a longitudinal slot closed at both ends, two spaced projections extending from said floating member at opposite sides of said slot, a resilient elastic member extending between the pins of the first plate, means :projecting from said floating member adjacent its opposite end bearing against said resilient means between its ends, for normally moving the floating member in a direction to seat said recess engaging means in any recess to which it comes, a short shaft extending into said housing through the outer closure, a member connecting to said shaft extending radially therefrom adjacent said floating member having a length so that all of said pins are in its path of movement, and means for manually turning said short shaft.

11. A structure as defined in claim 10, said generally circular plate having an inwardly extending slot at one side, a generally circular brake member bearing against the inner sides of said wall of the housing near the bottom thereof having an end extending into said slot and having its other end spaced from said first mentioned end of the brake member terminating in a section generally paralleling the adjacent wall, and an arm connected to said short shaft and movable therewith in the path of movement of the outer end of which said terminal section of the brake member is located.

12. A structure as defined in claim 11, said brake member consisting of a resilient length of metal having the end thereof connected with said plate in the slot thereof located generally radially with respect to said brake member, and said wall of the housing having a continuous V-shaped. groove therein in which said brake member is seated and against which it normally bears with resilient pressure, the other end of the metal REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Name Date Palmer Oct. 4, 1904,

Number 

